Discussed in my U.S. Pat. No. 4,764,272, entitled "Apparatus for Recovery of Hydrocarbons from Hydrocarbon/Water Mixtures", issued on Aug. 16, 1988, is apparatus for processing water from various sources where there is a major contamination of the water with hydrocarbons. These hydrocarbon contaminants can be either dissolved in, or mixed with, the water.
Then in my U.S. Pat. No. 5,069,796, entitled "System for Removing Volatile Components from Water Derived from Wells", issued Dec. 3, 1991, a system is discussed which is useful to process water that is less contaminated with hydrocarbons.
The systems of both of these patents utilize a stripping tower wherein there is countercurrent flow of forced air and a liquid containing the volatile components such that the volatile components are stripped from the liquid. In the '272 patent liquid product, after gross separation by gravity action, is collected in a generally open pan. This collected water is then picked up for a single pass of the liquid/volatiles mixture through a stripping tower where the mixture is passed countercurrently to forced air flow. The "processed" water is collected in the base of the tower. In the '796 patent the liquid (water) with the volatile contaminants is pumped directly into a similar stripping tower, with the processed water again being collected in the base of the stripping tower. In both patents the towers are operated intermittently when there is a demand with the water passing through the tower a single time, and in both the processed water is discharged from the systems by gravity when the quantity thereof exceeds an amount as determined by liquid level sensors in the respective collection devices.
During the continued use of the system of the '272 patent it has been found that often the quantity of initially processed water is relatively small that enters the collection pan from which it is to be pumped to the stripping tower. Thus, the stripping tower is only occasionally utilized and the pump associated therewith is often idle. As a result, since the system is usually at a remote site, there is increased potential for failure when the pump and tower are to be used. Further, if there is no contact for stripping the volatiles, they may remain within the water in the pan particularly since the amount of the volatiles can vary over wide ranges. In addition, there is always a potential problem of freezing of the water and thus damage to the equipment.
Accordingly, it is an object of the present invention to provide a stripping tower system that more efficiently removes volatile components, such as volatile hydrocarbons, from water containing the same.
It is another object of the present invention to provide a stripping tower system for the processing of water containing volatile components to remove these volatiles by contact with forced air wherein the stripping tower is continuously operated under all conditions of feed of the contaminated water whereby there are multiple passes of the water to enhance removal of the contaminants and reduce potential mechanical problems.
A further object of the present invention is to provide a stripping tower system for the separation of volatiles from a liquid, and particularly water, where excess processed water is discharged under pressure so as to be conveyed a greater distance for ultimate disposal in a collection device or utilization for irrigation, etc.
These and other objects of the present invention will become more apparent upon a consideration of the detailed description that follows when read together with the drawings identified hereinafter.